https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115412
Bug ID: 115412
Summary: ICE: canonical types differ for identical types
‘stdis_sametypename fooTtype, U’ and ‘stdis_sameT, U’
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: iamanonymous.cs at gmail dot com
Target Milestone: ---
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The compiler produces an internal error when compiling the provided code with
the specified options.
The issue involves canonical types differing for identical types during
template instantiation.
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OS and Platform:
# uname -a
Linux ubuntu 4.15.0-213-generic #224-Ubuntu SMP Mon Jun 19 13:30:12 UTC 2023
x86_64 x86_64 x86_64 GNU/Linux
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# g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/root/gdbtest/gcc/gcc-15/libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /root/gdbtest/gcc/obj/../gcc/configure
--prefix=/root/gdbtest/gcc/gcc-15 --enable-languages=c,c++,fortran,go
--disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.0 20240509 (experimental) (GCC)
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Program:
# cat main.cpp
#include <type_traits>
template<typename T>
struct foo {
using type = T;
template<
typename U
, typename std::enable_if<
std::is_same<type, U>::value
, int
>::type = 0
>
void bar(U&&);
};
template<typename T>
template<
typename U
, typename std::enable_if<
std::is_same<typename foo<T>::type, U>::value
, int
>::type
>
void foo<T>::bar(U&&) {}
int
main()
{}
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Command Lines:
# g++ main.cpp -O1 -c -o main.out
main.cpp:25:22: internal compiler error: canonical types differ for identical
types ‘std::is_same<typename foo<T>::type, U>’ and ‘std::is_same<T, U>’
25 | void foo<T>::bar(U&&) {}
| ^
0xd499c9 comptypes(tree_node*, tree_node*, int)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/typeck.cc:1710
0xd3cf8b cp_tree_equal(tree_node*, tree_node*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/tree.cc:4309
0xc9c3da template_args_equal(tree_node*, tree_node*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/pt.cc:9473
0xc9c105 template_args_equal(tree_node*, tree_node*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/pt.cc:9418
0xc9c105 comp_template_args(tree_node*, tree_node*, tree_node**, tree_node**)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/pt.cc:9499
0xd49826 structural_comptypes
/root/gdbtest/gcc/obj/../gcc/gcc/cp/typeck.cc:1522
0xd4993d comptypes(tree_node*, tree_node*, int)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/typeck.cc:1703
0xd49748 structural_comptypes
/root/gdbtest/gcc/obj/../gcc/gcc/cp/typeck.cc:1590
0xc99b2f comp_template_parms(tree_node const*, tree_node const*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/pt.cc:3349
0xb8361a check_classfn(tree_node*, tree_node*, tree_node*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/decl2.cc:878
0xb627e3 grokfndecl
/root/gdbtest/gcc/obj/../gcc/gcc/cp/decl.cc:11045
0xb69a7b grokdeclarator(cp_declarator const*, cp_decl_specifier_seq*,
decl_context, int, tree_node**)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/decl.cc:15114
0xb6d066 start_function(cp_decl_specifier_seq*, cp_declarator const*,
tree_node*)
/root/gdbtest/gcc/obj/../gcc/gcc/cp/decl.cc:18212
0xc83107 cp_parser_function_definition_from_specifiers_and_declarator
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:32780
0xc83107 cp_parser_init_declarator
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:23451
0xc8ae60 cp_parser_single_declaration
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:33420
0xc8b01c cp_parser_template_declaration_after_parameters
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:32973
0xc8b900 cp_parser_explicit_template_declaration
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:33246
0xc8b2e5 cp_parser_template_declaration_after_export
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:33265
0xc8b2e5 cp_parser_template_declaration_after_parameters
/root/gdbtest/gcc/obj/../gcc/gcc/cp/parser.cc:32959
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
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Also ICE on trunk, compiler explorer: https://godbolt.org/z/nzKP3Eovr
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